JFreeChart-FX time series vertical tick labels overlap

Question

When using jfreechart-fx to render a time series chart with vertical tick labels, the labels unexpectedly overlap the domain axis and sometimes change on resize. I can't reproduce this with Swing or pure Java2D, shown here. I'd welcome any guidance.

import java.awt.BasicStroke;
import java.awt.Color;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.stage.Stage;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.fx.ChartViewer;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYSplineRenderer;
import org.jfree.data.time.Day;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;

/**
 * @see https://stackoverflow.com/q/70021577/230513
 */
public class SplineTest extends Application {

    @Override
    public void start(Stage stage) throws ParseException {
        SimpleDateFormat inFormat = new SimpleDateFormat("yyyy-MM-dd");
        SimpleDateFormat outFormat = new SimpleDateFormat("dd-MM-yyyy");
        // data
        double[] values = new double[]{0.67, 0.67, 0.69, 0.70, 0.70, 0.71, 0.71};
        String[] dates = new String[]{"2021-11-09", "2021-11-10", "2021-11-11",
            "2021-11-12", "2021-11-15", "2021-11-16", "2021-11-17"};
        TimeSeries series = new TimeSeries("Time Series");
        for (int i = 0; i < values.length; i++) {
            Date date = inFormat.parse(dates[i]);
            series.add(new Day(date), values[i]);
        }
        TimeSeriesCollection dataset = new TimeSeriesCollection(series);
        // axes
        NumberAxis rangeAxis = new NumberAxis("Value");
        NumberFormat numberFormat = NumberFormat.getInstance();
        numberFormat.setMinimumFractionDigits(2);
        numberFormat.setMaximumFractionDigits(2);
        rangeAxis.setNumberFormatOverride(numberFormat);
        rangeAxis.setLowerMargin(0.08); // 8% lower margin
        rangeAxis.setAutoRangeIncludesZero(false);
        DateAxis domainAxis = new DateAxis("Date");
        domainAxis.setDateFormatOverride(outFormat);
        domainAxis.setVerticalTickLabels(true);
        // renderer, plot, chart
        XYSplineRenderer r = new XYSplineRenderer(15);
        XYPlot xyplot = new XYPlot(dataset, domainAxis, rangeAxis, r);
        JFreeChart chart = new JFreeChart(null, xyplot);
        r.setSeriesPaint(0, new Color(255, 152, 0));
        r.setSeriesStroke(0, new BasicStroke(2.0f));
        // display
        Scene scene = new Scene(new ChartViewer(chart));
        stage.setTitle("SplineTest");
        stage.setScene(scene);
        stage.setWidth(600);
        stage.setHeight(400);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

score 4 · Answer 1 · answered Nov 21 '21 at 19:45

The example cited uses a renderer for which no ChartFactory exists. These factories illustrate typical use cases; all end by applying a ChartTheme to the chart. The variation below applies a StandardChartTheme, which establishes coherent defaults for elements that affect geometry, such as font metrics and axis offsets; the defaults can be customized as shown.

The issue does not arise in pure Java2D, which runs on the initial thread. A similar Swing program is typically scheduled on the EventQueue. A jfreechart-fx program relies on a custom GraphicsContext; applying a ChartTheme ensures that the required defaults are present on the first update.

import java.awt.BasicStroke;
import java.awt.Color;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.stage.Stage;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.StandardChartTheme;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.fx.ChartViewer;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYSplineRenderer;
import org.jfree.data.time.Day;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;

/**
 * @see https://stackoverflow.com/a/70058016/230513
 * @see https://stackoverflow.com/q/70021577/230513
 */
public class SplineTest extends Application {

    @Override
    public void start(Stage stage) throws ParseException {
        SimpleDateFormat inFormat = new SimpleDateFormat("yyyy-MM-dd");
        SimpleDateFormat outFormat = new SimpleDateFormat("dd-MM-yyyy");
        // data
        double[] values = new double[]{0.67, 0.67, 0.69, 0.70, 0.70, 0.71, 0.71};
        String[] dates = new String[]{"2021-11-09", "2021-11-10", "2021-11-11",
            "2021-11-12", "2021-11-15", "2021-11-16", "2021-11-17"};
        TimeSeries series = new TimeSeries("Time Series");
        for (int i = 0; i < values.length; i++) {
            Date date = inFormat.parse(dates[i]);
            series.add(new Day(date), values[i]);
        }
        TimeSeriesCollection dataset = new TimeSeriesCollection(series);
        // axes
        NumberAxis rangeAxis = new NumberAxis("Value");
        NumberFormat numberFormat = NumberFormat.getInstance();
        numberFormat.setMinimumFractionDigits(2);
        numberFormat.setMaximumFractionDigits(2);
        rangeAxis.setNumberFormatOverride(numberFormat);
        rangeAxis.setLowerMargin(0.08); // 8% lower margin
        rangeAxis.setAutoRangeIncludesZero(false);
        DateAxis domainAxis = new DateAxis("Date");
        domainAxis.setDateFormatOverride(outFormat);
        domainAxis.setVerticalTickLabels(true);
        // renderer, plot, chart
        XYSplineRenderer r = new XYSplineRenderer(15);
        XYPlot xyplot = new XYPlot(dataset, domainAxis, rangeAxis, r);
        JFreeChart chart = new JFreeChart(null, xyplot);
        StandardChartTheme theme = new StandardChartTheme("Custom");
        theme.setPlotBackgroundPaint(Color.WHITE);
        theme.setDomainGridlinePaint(Color.LIGHT_GRAY);
        theme.setRangeGridlinePaint(Color.LIGHT_GRAY);
        theme.apply(chart);
        r.setSeriesPaint(0, new Color(255, 152, 0));
        r.setSeriesStroke(0, new BasicStroke(2.0f));
        // display
        Scene scene = new Scene(new ChartViewer(chart));
        stage.setTitle("SplineTest");
        stage.setScene(scene);
        stage.setWidth(600);
        stage.setHeight(400);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

JFreeChart-FX time series vertical tick labels overlap

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